Contactless switching apparatus

ABSTRACT

A contactless switching apparatus comprised of a magnetic strip both ends of which are bent to form opposed terminal portions, a magnetic piece which is fitted in said strip and is attracted at its both ends by said bent terminal portions, a supporting member which fixes either the strip or the magnetic piece to a base and hold it at a position a certain distance away from the base, an actuating means which actuates the rest, which is not fixed at the base, of the strip and magnetic piece and galvano-magneto effect devices which are provided at the ends of the fixed magnetic member, wherein the magnetic field intensity applied to the device is varied with movement of the movable magnetic member actuated by said actuating means.

United States Patent [191 Nishiba et al.

[ CONTACTLESS SWITCHING APPARATUS Inventors: Seishiro Nishiba; MasasiKuroyanagi, both of Tokyo; Koichi Ogawa, Yokohama, all of Japan DenkiOnkyo Co., Ltd., Tokyo, Japan May 23, 1972 Assignee:

Filed:

Appl. No.: 256,153

Foreign Application Priority Data May 24, 1971 Japan .l 46/42300References Cited UNITED STATES PATENTS Kobayashi 338/32 H Jan. 1, 19743,162,804 12/1964 Parsons .,324/45X 5 7 ABSTRACT A contactless switchingapparatus comprised of a magnetic strip both ends of which are bent toform opposed terminal portions, a magnetic piece which is fitted in'saidstrip and is attracted at its both ends by said bent terminal portions,a supporting member which fixes either the strip or the magnetic pieceto a base and hold it at a position a certain distance away from thebase, an actuating means which actuates the rest, which is not fixed atthe base, of the strip and magnetic piece and galvano-magneto effectdevices which are provided at the ends of the fixed magnetic member,wherein the magnetic field intensity applied to the device is variedwith movement of the movable "magnetic member actuated by said actuatingmeans.

17 Claims, 15 Drawing Figures PATENTED JAN I I 3. 7-83 .430

sum 2 OF 4 1 CONTACTLESS SWITCHING APPARATUS BACKGROUND OF. THEINVENTION The present invention relates to a contactless switchingapparatus employing a galvano-magneto effect device.

Conventional switching apparatuses of this type have been provided witha magnetic path formed by combining the magnetic fixed yoke and themagnetic movable yoke and the reluctance of the magnetic path has beenvaried by shifting the movable yoke actuated with an actuating meanssuch as a push button. The intensity of the magnetic field acting on thegalvano-magneto effect device has been changed with variation of thisreluctance to generate the output signal. Accordingly, conventionalswitching apparatuses are disadvantageous in the following points.

Since a plural number of yokes are required, the parts required increasein number, the production cost is high and assembly work is troublesomeand complicated. Since the magnetic path becomes large in size, theentire apparatus cannot be compacted.

Generally, the actuating means of a conventional apparatus is requiredto have a resetting spring. Therefore, the production cost is high andthe assembly work troublesome.

The present invention provides a switching apparatus which eliminatesthe above disadvantages.

SUMMARY A contactless switching apparatus comprising a high magneticpermeability strip both ends of which are bent to form a pair ofterminal portions, a magnetic piece such as, for example, a permanentmagnet having magnetic poles at its both ends which is fitted betweenthe terminal portions of said strip so that both ends of the magneticpiece are opposed respectively to said terminal portions of the stripwith agap at each side, a supporting member provided at one of saidstrip and magnetic piece, an actuating means provided at either thestrip or the magnetic piece at which the supporting member is notprovided, and a galvano-magneto effect device such as, for example,aHall effect device or a magneto-resistance effect device which is fixedat at least one end of the strip or the magnetic piece at the side wheresaid supporting member is provided so that the device is located in saidgap, wherein the supporting member is made and arranged so that themagnetic member supported by said supporting member is fixed at the baseand the magnetic member is held with a specified space between themagnetic member and the base, and said actuating means is designed sothat it may be isolated from the magnetic member at the fixing side byshifting said magnetic member held as above if desired, thereby themovable magnetic member provided with the actuating means is securedwhile being attracted at both ends by the fixing side magnetic memberalways held with the supporting member, is released from the fixing sidemagnetic member against the attracting force active on the fixing sidemagnetic member when actuated by the actuating means while beingkeptparallel with the fixing side magnetic member, and is reset to the homeposition by attraction to the fixing side magnetic member when releasedfrom the actuating means and saidgalvano-magneto effect device isconnected to the load which detects a galvano-magneto effect to detectthe variation of the output when the intensity of the magnetic fieldapplied to the device is varied by action of the moving side magneticmember and the output of the device is therefore varied.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is illustratedin detail by the accompanying drawings wherein: 1

FIG. 1 is a front view of the apparatus according to the presentinvention,

FIG. 2 is a sectional view as seen along line 2--2 FIG. 1,

FIG. 3 is a sectional view as seen along line 33 in FIG. 1,

FIG. 4 is isometric views of disassembled parts of the apparatus shownin FIG. 1,

FIG. 5 is a front view showing another embodiment of the apparatus,

FIG. 6 is a sectional view as seen along line 6-6 in FIG. 5,

FIG. 7 is a sectional view as seen along line 7-7 in FIG. 5,

FIG. 8 is an isometric view of a receiving member employed in theapparatus shown in FIG. 5,

FIG. 9 is an isometric view illustrating another embodiment of saidreceiving member,

FIG. 10 is an isometric view illustrating an embodiment of a push buttonemployed in the apparatus,

FIG. 11 is a horizontal sectional view of a switching apparatusemploying a push button shown in FIG. 10,

FIG. 12 is a front view illustrating another embodiment of theapparatus,

FIG. 13 is a cutaway side view of the apparatus shown in FIG. 12,

FIG. 14 is a circuit diagram of the apparatus employing thegaIvano-magnetro effect device, and

FIG. 15 is a circuit diagram of the apparatus employing the Hall effectdevice.

DETAILED DESCRIPTION Referring to FIGS. 1 to 4, there is shown aswitching apparatus comprised of actuating means 10 employing a pushbutton made ofa non-magnetic material, a magnetic piece 20 such as, forexample, permanent magnet which is vertically moved by said actuatingmeans, magnetic strip 30 into which said permanent magnet is fitted,supporting member 40'which supports said strip 30, galvano-magnetoeffect device 50 provided at said strip, guide frame 60 for movement ofsaid magnetic piece, and base such as, for example, a printed board onwhich said supporting member 40 and guide frame 60 are mounted.

Guide frame 60 is formed with a pair of U-shaped guide plates 61 and 61'made of a conductive material and a pair of said guide plates aremounted on base 70 so that a square space is formed between the guideplates by oppositely arranging bent free end 611 and 611".

Base 70 is provided with through holes 71 at positions where said guideplates are mounted and the guide plates are provided with claws 612 and612 at positions corresponding to through holes 71, thereby the guideplates are fixed at the base by inserting the claws into through holes71 and securing them.

Strip 30 is fixed at the space in guide frame 60 while being supportedby supporting members 40. Strip 30 is made of a high permeabilitymagnetic material and its both ends in the lengthwise direction are bentto form terminal portions 31 which are opposed each other. Strip 30 isinserted into the guide frame in the position that said terminalportions face base 70.

Supporting members 40 are provided at both sides in the center portionof strip 30 with the end portions of said supporting members beinginserted into through holes 72 provided at base 70.

Accordingly, strip 30 is held to oppose base 70 through a space with aspecified height.

Permanent magnet 20 is fitted into the underside of strip 30 so that thepermanent magnet can be slid vertically in a space between supportingmembers 40.

Permanent magnet 20 is magnetized so as to have magnetic poles N and Sat its both ends and these pole ends are assembled with strip 30 so thatthe pole ends are opposed respectively to terminal portions 31 of strip30 with gap G at each side. Accordingly, permanent magnet 20 is securedwhile its pole ends are usually attracted to the terminal portions ofstrip 30.

Permanent magnet 20 is operated by push button 10. Push button isprovided with mounting portions such as, for example, four pins 11 whichare extended to both sides of strip 30. Accordingly, strip 30 is housedin space 12 formed inside said pins 11.

Pins 11 are arranged so that they can slide along the internal surfacesof guide plates 61 and 61 of guide frame 60 and therefore movement ofpush button 10 is directionally controlled by guide plates 61 and 61'.

Permanent magnet 20 is fixed at the lower ends of pins 11 of push button10 with a bonding agent. Therefore, push button 10 is kept at the upperlimit position due to that permanent magnet 20 attracts strip 30.

Galvano-magneto effect device 50 such as, for example, amagnetro-resistance effect device is fixed at the inside surface of atleast one terminal portion 31 of strip 30 so that the device is opposedto one magnetic pole of permanent magnet 20.

Leads 51 are respectively connected to two electrodes of device 50 andare further connected to guide plates 61 and 61' respectively.

Since guide plates 61 and 61 are made of a conductive material, thedevice can be connected to detection circuit such as, for example,printed circuit 80 using the guide plates as the terminals by solderingclaws 612 and 612 to the printed circuit of base 70.

Circuit 80 can be formed as desired. For example, device 50 and load 81should be connected in parallel with supply V as shown in FIG. 14 if themagnetoresi'stance effect device is employedas the device, and load 81should be connected to output terminal 52 of the device as shown in FIG.15 if the Hall effect device is employed as the device.

In FIG. 14, if load 81 is a transistor, device 50 can be connected tothe base of the transistor to control the function of the transistorwith variation of the resissity applied to the device increases to causethe internal resistance of the device to increase. Accordingly, theoutput of the device varies with operation of push button 10, thusmaking it possible to perform the switching operation.

The apparatus can be constructedas described below. It is desirableto'attach cushion member such as, for example, a rubber plate to thesurfaces of strip 30 and magnetic piece 20. For example, as shown inFIG. 2, if rubber plates 90 and 90 are provided at the upper and lowersurfaces of strip 30, magnet 20 and push button 10 are buffered in theirmovement, and the relative position of the moving side magnetic member,that is, magnetic piece 20 shown in the embodiment to the terminalportion of said strip can be adjusted in accordance with the thicknessof rubber plate 90. At least one of magnetic piece 20 and strip 30 arepreferred to have a magnet; for example, a magnet can be employed instrip 30.

The magnetic piece which is actuated by actuating means 10 need not befixed directly to the actuating means. For example, as shown in FIGS. 5to 7, nonmagnetic receiving member can be attached to the push buttonmounting portion such as, for example, pins 11 and magnet 20 can beretained by this receiving member 100. The embodiment of said receivingmember 100 is shown in FIGS. 8 and 9. The receiving member shown in FIG.8 is a non-magnetic block provided with groove 101 into the center ofwhich the magnet is fitted, through holes 102 into which pins 11 areinserted at both sides of groove 101 and cut-off window 103 into whichsupporting member 40 can be slid at the center bottom of the groove.This receiving member is employed in the apparatus shown in FIG. 5.

The receiving member shown in FIG. 9 is such that both sides of thecenter of groove 101 are chipped and supporting member 40 slides alongthe chipped portions, thus forming slide recess 104. This receivingmember is used as that shown in FIG. 8.

The mounting portion of said push button 10 can be formed with a pair ofopposed walls 13 and 13' as shown in FIG. 10. In this case, the fixingside magnetic member is provided in the space between a pair ofwalls asshown in FIG. 11 and recesses 131 along which supporting member 40slides are provided at the internal surfaces of walls 13 and 13'.

Either magnetic piece 20 or strip 30 can be fixed.

As shown in FIGS. 12 and 13, strip 30 is attached to push button as themoving side and magnetic piece 20 can be fixed at base 70 withsupporting member 40. In this case, terminal portions 31 of strip 30 areprojected upwardly because strip 30 moves vertically and magnetic piece20 is housed in cavity 14 formed in the push button when the push buttonis lowered.

In this embodiment, the mounting portion is formed with peripheral wall15 inside which cavity 14 is formed and the peripheral wall is arrangedto lightly contact the guide plates to improve directional control ofmovement.

In this type of the apparatus, since the push button is provided withthe strip, the total weight of the push button and strip is reduced andthe magnetic piece can be large and a large magnet can be employed asthe fixing side magnetic member.

In the above embodiments, each area of the terminal portions of thestrip and the end portions of the magnetic piece which form the gap inwhich the device is located is preferred to be larger than that of thedevice and the magnetic piece preferably projects from the terminalportions as shown in FIG. 2 to improve the resetting ability.

If the fixing side magnetic member is employed as the strip as shown inFIG. 1, supporting member 40 can be made integral with the strip but canbe independent of the strip, depending on the case. If the magnet isemployed as the fixing side magnetic member, the nonmagnetic supportingmember is generally employed.

Since the apparatus according to the present invention is as describedabove, it provides the following advantages when employed.

The resetting means such as, for example, a spring is not requiredbecause the moving side magnetic member is secured by being attracted tothe fixing side magnetic member.

Because the magnetic path is formed by fitting the magnetic piece intothe strip, the magnetic path can be compact in size and since themagnetic path can be formed with the magnetic piece and strip only, theparts employed can be reduced in number and assem' bly work is easy.

Because the magnetic path is opened and closed with mutual approach-anddeparture of the strip and the magnetic piece whichare kept in parallel,the stroke of the moving side magnetic member can be small and theterminal portions ofthe strip and the end portions of the magnetic pieceapproach each other or depart from each other at the same time;therefore, the reluctance of the magnetic path greatly varies andcorrespondingly the magnetic flux density applied to the device.

The apparatus according to the present invention iss useful as thecontactless switching apparatus for which the demand will increase moreandmore in the future for the advantages described above.

What is claimed is:

l. A contactless switching apparatus comprising:

a. A magnetic strip having a pair of ends bent to form opposed terminalportions,

b. a magnetic piece having a pair of ends, inserted between the terminalportions of said magnetic strip, each of said ends respectively opposinga different one of said terminal'portions and being separated therefrombya gap, said magnetic piece and said magnetic strip being reciprocallydisplaceable along a predetermined path, one of said magnetic piece andsaid magnetic strip being a fixed magnetic member and the other being amovable magnetic member,

0. a base,

d. a supporting member attached between said base and said fixedmagnetic member to'provide a space therebetween,

e. at least one galvano-magneto effect device within one of said gapsformed between said magnetic stripand said magnetic piece, wherein saidgalvano-magneto effect device is positioned in the flux path between themagnetic strip and the magnetic piece,

f. a depressible push button actuating means adapted to displace alongsaid pre-determined path said movable magnetic member whereby themagnetic flux density through said galvano-magneto effect device ischanged.

2. An apparatus according to claim 1, wherein said depressible pushbutton actuating means is provided with a mounting portion for holdingthe movable magnetic member.

3. An apparatus according to claim 2, wherein the mounting portion iscomprised of a plurality of pins between whichthe movable magneticmember is fixed.

4. An apparatus according to claim 2, wherein the mounting portion iscomprised of a pair of oppositelyarranged walls, the fixed'magneticmember being disposed in the space formed therebetween, the walls havingon the internal surfaces thereof recesses for slidably engaging thesupporting member.

5. An apparatus according to claim 2, wherein the mounting portion is aperipherally enclosing wall forming an open-ended cavity in the pushbutton actuating means, the ends of the magnetic strip are fixed at thelower end of the peripherally enclosing wall and the magnetic piece ispositioned inthe open-ended-cavity of the push button actuating means.

6. An apparatus according to claim 3, wherein the mounting portion isprovided with a receiving member supporting the movable magnetic member.

7. An apparatus according to claim 6, wherein the receiving member'is ablock at the center of which is a groove receiving the magnetic piece.

8. An apparatus according to claim 7, wherein through holes for securingthe pins of the push button actuating means are provided at both sidesof the groove and a cut-off window is provided at the center of thebottom of the groove to slidably receive therein the supporting member.

9. An apparatus according to claim 7, wherein through holes into whichthe pins of the push button actuating means are fixed are provided atboth sides of the groove and recesses along which the supporting memberslides are provided at both sides of the center of the groove.

10. An apparatus according to claim 1, wherein the magnetic strip isfixed by the supporting member so that the terminal portions arepositioned to face the base and the magnetic piece is movably positionedin the space between the magnetic strip and the base.

11,. An apparatus according to claim 1, wherein a cushion member isprovided at at least one of the magnetic strip and piece so that thecushion member is positioned between the magnetic strip and piece whenthe magnetic strip is attracted to the magnetic piece.

12. An apparatus according to claim 1, wherein a guide frame is providedatthe base so that the direction of movement of the movable magneticmember is controlled.

13. An apparatus according to claim 12, wherein the guide frame iscomprised of a pair of opposed guide plates, the mounting portion of thepush button actuating means is inserted into a space formed between saidguide plates and moves vertically therebetween with the mounting portionkeeping light contact with the in- 'ternal surfaces of the opposed guideplates.

14. An apparatus according to claim 12, wherein the guide frame iscomprised of a pair of opposed guide plates and a receiving member isinserted into a space formed between said guide plates and movesvertically while keeping light contact with the internal surfaces of theguide plates. 1

15. An apparatus according to claim 12, wherein the guide frame iscomprised of a pair of conductive guide plates, lead wires of agalvano-magnetro effect device are connected respectively to said guideplates and the 3,783,430 7 8 guide plates are connected respectively toan electrical magnetic piece is the movable magnetic member and circuitprovided at the base. I

16. An apparatus according to claim 15, wherein the base includes aprinted circuit. fixed magnet: member 17. An apparatus according toclaim 1, wherein the composed of a magnet and the magnetic strip is the

1. A contactless switching apparatus comprising: a. A magnetic striphaving a pair of ends bent to form opposed terminal portions, b. amagnetic piece having a pair of ends, inserted between the terminalportions of said magnetic strip, each of said ends respectively opposinga different one of said terminal portions and being separated therefromby a gap, said magnetic piece and said magnetic strip being reciprocallydisplaceable along a predetermined path, one of said magnetic piece andsaid magnetic strip being a fixed magnetic member and the other being amovable magnetic member, c. a base, d. a supporting member attachedbetween said base and said fixed magnetic member to provide a spacetherebetween, e. at least one galvano-magneto effect device within oneof said gaps formed between said magnetic strip and said magnetic piece,wherein said galvano-magneto effect device is positioned in the fluxpath between the magnetic strip and the magnetic piece, f. a depressiblepush button actuating means adapted to displace along saidpre-determined path said movable magnetic member whereby the magneticflux density through said galvano-magneto effect device is changed. 2.An apparatus according to claim 1, wherein said depressible push buttonactuating means is provided with a mounting portion for holding themovable magnetic member.
 3. An apparatus according to claim 2, whereinthe mounting portion is comprised of a plurality of pins between whichthe movable magnetic member is fixed.
 4. An apparatus according to claim2, wherein the mounting portion is comprised of a pair ofoppositely-arranged walls, the fixed magnetic member being disposed inthe space formed therebetween, the walls having on the internal surfacesthereof recesses for slidably engaging the supporting member.
 5. Anapparatus according to claim 2, wherein the mounting portion is aperipherally enclosing wall forming an open-ended cavity in the pushbutton actuating means, the ends of the magnetic strip are fixed at thelower end of the peripherally enclosing wall and the magnetic piece ispositioned in the open-ended cavity of the push button actuating means.6. An apparatus according to claim 3, wherein the mounting portion isprovided with a receiving member supporting the movable magnetic member.7. An apparatus according to claim 6, wherein the receiving member is ablock at the center of which is a groove receiving the magnetic piece.8. An apparatus according to claim 7, wherein through holes for securingthe pins of the push button actuating means are provided at both sidesof the groove and a cut-off window is provided at the center of thebottom of the groove to slidably receive therein the supporting member.9. An apparatus according to claim 7, wherein through holes into whichthe pins of the push button actuating means are fixed are provided atboth sides of the groove and recesses along which the supporting memberslides are provided at both sides of the center of the groove.
 10. Anapparatus according to claim 1, wherein the magnetic strip is fixed bythe supporting member so that the terminal portions are positioned toface the base and the magnetic piece is movably positioned in the spacebetween the magnetic strip and the base.
 11. An apparatus according toclaim 1, wherein a cushion member is provided at at least one of themagnetic strip and piece so that the cushion member is positionedbetween the magnetic strip and piece when the magnetic strip isattracted to the magnetic piece.
 12. An apparatus according to claim 1,wherein a guide frame is provided at the base so that the direction ofmovement of the movable magnetic member is controlled.
 13. An apparatusaccording to claim 12, wherein the guide frame is comprised of a pair ofopposed guide plates, the mounting poRtion of the push button actuatingmeans is inserted into a space formed between said guide plates andmoves vertically therebetween with the mounting portion keeping lightcontact with the internal surfaces of the opposed guide plates.
 14. Anapparatus according to claim 12, wherein the guide frame is comprised ofa pair of opposed guide plates and a receiving member is inserted into aspace formed between said guide plates and moves vertically whilekeeping light contact with the internal surfaces of the guide plates.15. An apparatus according to claim 12, wherein the guide frame iscomprised of a pair of conductive guide plates, lead wires of agalvano-magnetro effect device are connected respectively to said guideplates and the guide plates are connected respectively to an electricalcircuit provided at the base.
 16. An apparatus according to claim 15,wherein the base includes a printed circuit.
 17. An apparatus accordingto claim 1, wherein the magnetic piece is the movable magnetic memberand composed of a magnet and the magnetic strip is the fixed magneticmember.